New analysis sharpens view of cosmic birefringence and universe symmetryby Clarence OxfordLos Angeles CA (SPX) Jan 29, 2026A research team has developed a method to reduce uncertainties in measurements of cosmic birefringence, a subtle rotation in the polarization of the cosmic microwave background that may hold clues to new physics beyond the standard model. Cosmic birefringence refers to a small rotation in the polarization direction of the cosmic microwave background, the relic radiation from the Big Bang that preserves information about the early universe. A companion paper by Naokawa, also appearing January 27 in Physical Review Letters, tackles a different source of error in cosmic birefringence measurements the distortions introduced by the telescopes themselves. The second study proposes strategies to overcome these telescope induced errors and isolate the genuine cosmic signal. In that separate work, Naokawa demonstrates that specific classes of celestial objects can provide an independent check on cosmic birefringence beyond the CMB.